NoClassDefFoundError: com.mysql.cj.jdbc.Driver error due to using mysql 5.1.XX version

[enkeebbx]

The required mysql version for this project based on its documentation is 5.1.XX, but the project tries to find com.mysql.cj.jdbc.Driver and fails upon run. This error calls for inspection.

@spring-operator @sobychacko @tzolov

[sabbyanandan]

Hi, @enkeebbx. Could you update the description with what version is in use, error stacktrace, and the details on how you're attempting to run it?

[enkeebbx]

Sure, @sabbyanandan!

I followed this quick start tutorial https://github.com/tzolov/cdc-debezium/blob/master/spring-cloud-starter-stream-common-cdc-debezium/cdc-debezium-spring-boot-starter/README.adoc and added the following dependencies to my pom.xml.

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud.stream.app</groupId>
            <artifactId>cdc-debezium-spring-boot-starter</artifactId>
            <version>2.1.1.BUILD-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
    </dependencies>

However, upon mvn spring-boot run, I got :

Unable to initialize and start connector's task class 'io.debezium.connector.mysql.MySqlConnectorTask' with config: {name=my-sql-connector, offset.commit.policy=io.debezium.embedded.spi.OffsetCommitPolicy$PeriodicCommitOffsetPolicy, connector.class=io.debezium.connector.mysql.MySqlConnector, database.server.id=85744, database.port=3306, offset.storage=org.springframework.cloud.stream.app.cdc.common.core.store.MetadataStoreOffsetBackingStore, database.user=****, database.hostname=*****, database.password=********, database.history=io.debezium.relational.history.MemoryDatabaseHistory, offset.flush.interval.ms=60000, database.server.name=my-app-connector, offset.flush.timeout.ms=5000}

java.lang.NoClassDefFoundError: com/mysql/cj/jdbc/Driver
    at io.debezium.connector.mysql.MySqlConnectorConfig.<clinit>(MySqlConnectorConfig.java:695) ~[debezium-connector-mysql-0.9.2.Final.jar:0.9.2.Final]
    at io.debezium.connector.mysql.MySqlConnectorTask.getAllConfigurationFields(MySqlConnectorTask.java:444) ~[debezium-connector-mysql-0.9.2.Final.jar:0.9.2.Final]
    at io.debezium.connector.common.BaseSourceTask.start(BaseSourceTask.java:38) ~[debezium-core-0.9.2.Final.jar:0.9.2.Final]
    at org.springframework.cloud.stream.app.cdc.common.core.EmbeddedEngine.run(EmbeddedEngine.java:804) ~[spring-cloud-starter-stream-common-cdc-debezium-core-2.1.1.BUILD-SNAPSHOT.jar:2.1.1.BUILD-SNAPSHOT]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_171]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_171]
    at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_171]
Caused by: java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_171]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_171]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_171]
    ... 7 common frames omitted

Here is my application.properties that I wrote accordingly:

cdc.name=my-sql-connector
cdc.connector=mysql

cdc.config.name=my-sql-connector
cdc.config.database.history=io.debezium.relational.history.MemoryDatabaseHistory
cdc.config.database.server.id=85744
cdc.config.database.server.name=my-app-connector
cdc.config.database.user=****
cdc.config.database.password=****
cdc.config.database.hostname=****
cdc.config.database.port=3306

cdc.schema=false

cdc.flattering.enabled=true

[sabbyanandan]

Thanks for the update, @enkeebbx. We will review it.

[tzolov]

Hi @enkeebbx , finally i got time to check this. It appears that the problem is due to to wrong versions for both dc-debezium-spring-boot-starter and the mysql-connector-java. Here are the correct versions that work form me:

        <dependency>
            <groupId>org.springframework.cloud.stream.app</groupId>
            <artifactId>cdc-debezium-spring-boot-starter</artifactId>
            <version>1.0.0.BUILD-SNAPSHOT</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>

E.g. 1.0.0.BUILD-SNAPSHOT for the starter (the 1.0.0.M1 might work as well) and 8.0.13 for the mysql-connector. I've updated the poms and docs: https://github.com/spring-cloud-stream-app-starters/cdc-debezium/tree/master/spring-cloud-starter-stream-common-cdc-debezium/cdc-debezium-spring-boot-starter

Also unless you are compiling it locally you may want to add the Spring snapshot (and or milestone) maven repos :

    <repositories>  
        <repository>
            <snapshots>
                <enabled>true</enabled>
            </snapshots>
            <id>spring-snapshots</id>
            <name>Spring Snapshots</name>
            <url>https://repo.spring.io/snapshot</url>
        </repository>
        <repository>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

Please let me know if this resolves your problem.